Fairfield police disclosed little Saturday about the apparent killing of a 13-year-old girl whose nude body was found in a popular city park the morning after she had been reported missing in nearby Suisun City.

Police did not release the girl's name or cause of death, nor would they discuss details of her disappearance Thursday. Officer Cleo Mayoral, Fairfield police spokesman, said the name was being withheld because of her age and because she was a foster child, which has complicated notification of her family.

The cause of death, determined by the Solano County coroner Friday night, was also not being released as the investigation continues. Police did say, however, that there were no visible signs of trauma to the body.

"It is a very intense investigation, and it's going nonstop," Mayoral said. "We have all of our resources working on this."

No suspects have been identified, Mayoral said, but investigators are analyzing video from cameras in the park, as well as at nearby businesses. They've also fanned out in nearby neighborhoods looking for anyone who may have seen the victim.

The girl was reported missing around 5:45 p.m. Thursday by a foster parent who had not seen her since she boarded a bus for Green Valley Middle School in Fairfield that morning. A fellow student, who did not want to be identified, said she was at school Thursday.

Her body was discovered about 5:45 a.m. Friday in the median of a parking lot in Alan Witt Park. Police scoured the park looking for evidence and returned Saturday, rummaging through garbage cans.

Nearby, about 30 feet from where the girl's body was found, a small memorial of candles, cards, flowers and stuffed animals grew as a steady trickle of both strangers and friends dropped by.